The S&P 500 sank 1.5 percent to 1,935.09 at 4 p.m. in New York, the lowest level since Aug. 12. Today’s slide was the biggest in almost three weeks. Selling accelerated in afternoon trading as index futures contracts expiring in December slipped below 1,940, a level where two previous declines had ended earlier today.

U.S. stock-index futures declined, with the Standard & Poor’s 500 Index (CME:SPZ14) poised to drop a second day, amid further signs of slowing growth in Europe and as investors await corporate earnings reports to assess the strength of the American economy.

Stronger demand for goods and services is prompting companies to hold the line on firings and expand headcount. Continued progress in the labor market will be needed to boost aggregate income and drive consumer spending, which accounts for almost 70 percent of the economy.

Our prompt assertion in June that the forward view within the SEP was more important than media headlines pointing to an imminent policy tightening were lost even more recently when the San Francisco Fed posted its paper on public expectations of policy.

The Fed has said since March interest rates would stay low for a period after it completes a bond-buying program under the quantitative-easing stimulus strategy. Policy makers in July reduced monthly bond purchases to $25 billion in their sixth consecutive $10 billion cut.